Note 4 battery life and buying a new battery

I was wondering if I buy a new batter will they change? Mine seems like it kinda goes down faster than I expect, but I'm not sure. Can the only problem be in the battery? I wanted to ask this because I am not sure if a poor battery life is thanks to the battery only or there are other components of the phone that may reduce it?

It would also help to see the screen that shows the battery usage breakdown by apps (in English would be ideal). You might have an app that is using too much battery, like Facebook (which has been a battery hog in recent versions).